Apparatus for the utilization of waste heat



G. YATES July 21, 1936.

APPARATUS FOR THE UTILIZATION OF WASTE HEAT Filed Aug. 26, 1935 3 Sheets-Sheet 1 To SUPPLY 77mm 1 Liz G. YATES July 21, 1936.

APPARATUS FOR THE UTILIZATION OF WASTE HEAT 1955 5 Sheets-Sheet 2 Filed Aug. 26

G. YATES July 21, was.

APPARATUS FOR THE UTILIZATION OF WASTE HEAT Filed Aug. 26, 1935 3 Sheets-Sheet 3 Icon/M Jilbtgawsfraw furnace Patented July 21, 1936 UNITED STATES PATENT OFFICE APPARATUS FOR THE UTILIZATION OF wAsT HEAT 6 Claims.

This invention relates to an apparatus for the utilization of waste heat.

An object of the invention is the provision of an apparatus which is adapted to be placed within an enlarged chamber of aflue and includes a pair of headers connected with the boiler of the furnace and a pair of spaced headers connected with a storage tank for water, tubes connecting the first-mentioned pair of headers and passing through tubes which connect the second-mew tioned pair of headers so that as the exhaust gases pass through the chamber the heat of the gases is utilized for increasing the temperature of the water in the boiler and also the water in the storage tank.

Another object of the invention is the provision of an apparatus adapted to be placed in an enlarged chamber of a flue for utilizing the heat of the exhaust gases passing through the flue for not only increasing the temperature of the water in the boiler but for increasing the temperature of the water in a storage tank.

' A further object of the invention is the provision of an apparatus adapted to be placed in an enlarged chamber of a fiue connected with a furnace in which a pair of closely associated headers are located at the top of the chamber and a pair of spaced headers in close association are located at the bottom of the chamber, tubes connecting a header at the top of the chamber with a header at the bottom of the chamber, other tubes connecting the remaining headers and passing not only through the first-mentioned tubes but also passing through the first-mentioned pair of headers, the first-mentioned pair of headers being connected with a storage tank for water, the last-mentioned pair of headers being connected with the boiler.

This invention will be best understood from a consideration of the following detailed description, in view of the accompanying drawings forming a part of the specification; nevertheless, it is to be understood that the invention is not confined to the disclosure, being susceptible of-such changes and modifications as define no material departure from the salient features of the invention as expressed in the appended claims.

In the drawings:

Figure 1 is a view in elevation partly in section of one form of an apparatus for utilizing the waste heat from the storage.

Figure 2 is a fragmentary horizontal section taken along the line 2-2 of Figure 1,

Figure 3 is a view in elevation of another form of the apparatus shown connected with a furnace and boiler with parts in section,

Figure 4 is a horizontal section taken along the line 44 of Figure 3,

Figure 5 is a vertical section of another form 5 of the apparatus for utilizing waste heat,

Figure 6 is a horizontal section taken along the line 6-6 of Figure 5.

Figure 7 is a central vertical section of a further modification of the foregoing apparatus, Figure-8 is a cross section of said apparatus taken on the line 8-8 of Figure 7.

Referring more particularly to the drawings, 10 designates an enlarged chamber forming part of a flue I! of a furnace through which the hot gases from the furnace pass before they are discharged into the atmosphere. A damper I2 is provided in the upper end of the fine to control the flow of the hot exhaust gases from the chamber.

A header I5 is located at the upper end of the chamber l0 and a similarly constructed header I8 is located at the lower end of the chamber. These headers are connected by a plurality of tubes H which extend vertically and are in communication with said headers.

A pipe I8 is connected at one end with the header l6 while the other end of the pipe is connected with the lower end of the storage tank for water. The pipe l8 forms a communication between the storage tank (not shown) and the header i6 so that water from the storage tank will flow through the header. A pipe 19 connects the header IS with the upper end of the storage tank, as shown, and forms a communication between the header and the storage tank so that as the water is heated in the headers it will pass from the headers l5 through the pipe l9 to the storage tank.

A header 20 is located at the bottom of the 0 chamber Ill while a header 2| is located at the top of the header 20 and is disposed in close association with the headers I6 while the header 2! is closely associated with the header I5 for a purpose which will be presently explained. A

pipe 22 connects the header 20 with the boiler of a furnace while the header 2| is connected by a pipe 23 with a riser from the boiler. The pipe 22 forms an outlet for the water in the header 20 whereby the water 'is discharged into the boiler. The pipe 23 conducts water from the riser to the header 2 I.

In each of the tubes I! is placed a tube 25 which is disposed in parallel relation with the tube H and the opposite ends of the tube pass through the headers l5 and I6, respectively, and are in communication respectively with the headers 20 and 2|.

The headers l5, I6, 2|, and 20 may be of any shape but in this instance are elongated and extend across the central portion of the chamber l0.

As the hot gases pass into the chamber Hi from the furnace they circulate through the pipe I! and around the pipes and also the pairs of headers at the top and bottom of the chamber Ill. The water in the headers and also in. the tubes absorbs the heat for raising the temperature of the water. It will be noted that the headers 20 and 2| are exposed to the hot gases as are the headers l5 and IS. The tubes I, however, are only exposed to the hot gases while the tubes 25, which are located in the tubes absorb heat from the water passing through the tubes l1. 4

It will be seen by this apparatus that a great deal of the heat which is ordinarily discharged v the Water in the boiler of the furnace but for heating the water in the usual storage tank. The usual storage tank, however, may be connected with a coil in the furnace so that the additional heat units are obtained from the waste gases which ascend the flue while additional heat units are also supplied to the water in the boiler of the furnace.

Referring more particularly to Figs. 3 and 4 it will be seen that a modified form of the invention is disclosed and an enlarged chamber 30 provided in the flue 3| and the flow of gases through the chamber is controlled by a damper 32 operated by a shaft 33. The hot gases pass through a pipe 34 from the firebox 35 of a furnace designated generally by the numeral 36 and enter the chamber 30 through an opening 31.

A riser 38 is connected with a boiler 33 of the furnace 36 and extends upwardly and acts as a return pipe for the cooler water of the hot water system in a building.

A pair of headers 4|! and 4| are located respectively at the top and bottom of the chamber 30 and these headers are substantially circular as shown in Fig. 4.

Tubes 42 connect the headers 40 and 4| so that these headers are in direct communication with each other.

A header 43 is in close association with the header 40 while a header 44 is-in close association with a header 4|. These headers are also circular. Tubes 45 connect the headers 43 and 44 together and pass axially of the tubes 42 and since the tubes 45 have less cross sectional area than the tubes 42, the spaces provided between the concentric tubes permit water to flow from the header 4!) to the header 4|.

, A pipe 46 is connected with a header 40 and with a storage tank so that the water from the said header will pass to the storage tank. A pipe 41 also connects the storage tank (not shown) with a header 4| so that the cooler water from the storage tank will pass to the header 4|. A pipe 48 connects the header 44 with the boiler 39 and provides means for the passage of the water from the header to the boiler. A pipe 49 connects the riser 38 with a header 43 so that cooler water from the return pipe 38 will pass to the header 43, thence through the tubes 45 and into the header 44 whence this water will pass through the pipe 38 to the boiler 39 of the furnace.

In view of the fact that the headers 40, 4|, 43 and 44 are circular, the tubes 42 and 45 will be arranged around the circumference of a circle so that the hot gases from the pipes 34 will pass through the center of the headers and exteriorly of the headers and around the tubes 42.

A further modified form of the invention is shown in Figs. 5 and 6 and includes the chamber 50 which is an enlargement of the flue 5| which contains a damper 52 for checking the flow of the hot gases through the flue so that there will be heat-interchange between the gases and the water contained in a heater generally designated by the numeral 53. A pipe 54 is in open communication with the bottom of the chamber 50 and this pipe is connected with the furnace for conducting hot gases from the furnace to the chamber 50 for a purpose which will be presently explained.

The water heater consists of an annular chamber 55 having a central passage 56. This chamber is connected by a pipe 51 with a supply tank 10 whereby water is conducted from the annular chamber 55 to the storage tank. A pipe 58 connects the lower end of the storage tank with the annular chamber 55 so that the cooler water from the tank may be conducted to the annular chamber to be heated. An annular chamber 60 is located concentrically within the chamber 53 and is connectediby a pipe 6| with the-return pipe of a hot water system whereby the cooler water from the-system may enter the chamber BI) and be heated. A pipe 62 connects the chamber 60 with the boiler in the furnace and conducts the water from the chamber to the boiler. Hot gases from the furnace pass through the pipe 54, through the central passage 56, the outer section of the chamber 50 whereby the water in the annular chamber 55 will be heated and there will be a heat-interchange relation between the water in the annular chamber 55 and the annular chamber 6|! for heating the water in the chamber 60 whichis conducted to the boiler of the furnace.

Attention is next directed to the further modification of the apparatus in Figures '7 and 8. The flue 63 from the furnace discharges its hot gases into an enlarged chamber 64 prior to their escape to atmosphere by way of the continuation 65 of the flue, said continuation having a damper 65a, all as in the preceding instances. The water heater 66 again consists of an annular chamber which has a central passage 61. The ends of the annular space between the outer and inner walls of the heater are closed by header plates 68, and it is to these plates that a cylindrical partition 69 is secured at its ends so as to divide the internal heater space into a pair of entirely separate, annular water compartments 10, 1|.

Pipes l2, 13, respectively from and to the boiler are fitted into the header plates 68 so as to communicate with the innermost compartment 1|, said compartment, therefore, containing very hot water from the boiler. other pipes 14, I5, respectively from and to the supply tank, are fitted into the outer wallof the heater so as to communicate with the outermost compartment 10 at points adjacent to the remote header plates.

The result of the foregoing arrangement is to cause the water from the supply tank to take very quickly, and the boiler water is prevented from losing any perceptible'amount of its heat because of the header plates, which define the ends of the boiler water-compartment, being situated well within the confines of the chamber 04,

I claim:

1. In a furnace, a flue, an enlarged chamber forming part of the flue, pairs of headers at the top and bottom of the chamber, the headers 01 each pair being in contact with each other, tubes connecting a header at the top with a header at the bottom, tubes passing through the firstmentioned tubes and connected at the opposite ends thereof with the other headers, the flrstmentioned headers being in communication with a boiler of the furnace, the second mentioned headers being in communication with a storage tank for water, said headers being circular, the two sets of tubes being arranged in circular rows.

2. In a furnace having a boiler and storage tank for water, a flue having an enlarged chamber, a pair of spaced headers in the chamber, tubes connecting the headers and having connections with a hot water storage tank, a second pair of spaced headers, tubes connecting the secondmentioned headers and passing through the firstmentioned tubes and headers, the second-mentioned tubes having less cross-sectional area than the first-mentioned tubes to provide a passage for water in the said tubes, and pipes connected with the second-mentioned headers for connecting said headers with the boiler of the furnace.

3. In a furnace having a boiler and storage tank for water, a flue having an enlarged chamber, a pair of headers at one end of the chamber and in contact with each other, a pair of headers in contact with each other and located in the other end of said chamber, tubes connecting a header of each pair, pipes connecting said headers with the storage tank, tubes, passing through the first-mentioned tubes and connecting the headers of the other pair, and pipes connecting the last-mentioned headers with the boiler.

4. In a furnace having a boiler and a storage tank for water, a flue having an enlarged chamber, a pair of water heaters in the chamber, one heater having vertical portions disposed concentrically within the other heater, the last-men- 5 tioned heater having the walls thereof exposed to the hot gases from the furnace and forminga passage for the hot gases, one of the heaters having connections with the storage tank, the other heaterhaving connections with the boiler.

5. In a furnace having a boiler and a storage tank for water, a flue having an enlarged chamber, an annular water chamber in the flue chamber having connection with the storage tank, the water chamber having a central passage for hot combustion gases from the furnace and the outer walls spaced from the walls of the flue chamber to providean annular passage for hot gases, an annular chamber within the water chamber and having its concentric walls spaced from the wall of the water chamber, and pipes connecting the last-mentioned chamber with the boiler.

6. In a furnace having a boiler and storage tank for water, a fine having an enlarged chamber, a heater for the storage tank water, said heater being located in said enlarged chamber and consisting of outer and inner concentric walls defining an annular space, header plates closing the ends of. said space, a cylindrical partition situated in and dividing said annular space into so inner and outer water compartments, the ends of said partition being secured to, the header plates, pipe connections between the boiler and the remote ends of the inner compartment, and other pipe connections between the storage tank and the remote ends of the outer compartment, the water in the outer compartment taking a. course between the hot furnace gases in the enlarged chamber and the boiler water in the inner compartment.

GEORGE YATES. 

